Head for enameled tanks



' July 27, 1943. J. M; FLOYD HEAD FOR ENAMELED TANKS Filed May 6, 1940 John M. Floyd INVENT OR.

ATTORNEY.

Patented July 27, 1943 K UNITED STATES PATENT OFFICE 2,325,497 HEAD FOR ENAMELED TANKS John M. Floyd, Shorewood, Wis., assignor to A. O. Smith Corporation, Milwaukee, Wis., a corporation of New York Application May 6, 1940, Serial No. 333,620 1' Claim. (01. 220-63) This invention relates to heads for tanks proexposed to the inside of the tank. The enamel vided with a vitreous enamel lining. on the flange 2 should stop short of the position An object of the invention is to provide an imat which weld 4 is to be made. The head is proved form of head for tanks of this character. then inserted in the flared end of the previously A further object of the invention is to pro- 5 enameled shell 3 and welded in place. vide a head resistant to deflection and deforma- The corrugations have the function of stiffention which might crack off the enamel lining. ing the head and making it resistant to deforma- These and other objects of the invention will tion by the Water Pressure inside e tank. This be clear from the following description and the stiffening effect would be needed but little, if at accompanying drawing in which: all, in a full dished head approximately semi- Figure 1 is a plan view of a head formed in elliptical in shape on a diametral section and accordance with this invention; united to the shell as shown diagrammatically Fig. 2 is a section on the line 2--2 of Fig. 1; in Fig. 4, in which 8 is the dished head, 9 the Fig. 3 is a section on the line 3-3 of Fig. 1;, e a d l a e uniting the Water and 5 pressure acting in the direction of the arrows Figs. 4 and 5 are diagrams illustrating the has but little tendency to deform either the shell actions of water pressure on heads of different or head unless the pressure is high enough to exshapes. pand the tank as a whole. This is, of course, a Vitreous enamel is found to be an'excellent situation which should never arise in practice lining material for hot water tanks, resistant to go as the shell and head must have a suflicient the corrosive action of water, permanent, and apthickness of metal to keep the stress below the pliable at a cost not greatly in excess of galyield point. Ahead and shell COIlS'GluCtlOIl SllCh vanizing which gives. far less effective protection. as that S w diagrammatically in would,

For best results, however, the tank should be so therefore, be hi hly esirable for vitreous enamfabricated as to be free from stress concentration eled tanks and in fact, used h complete and resistant to deformation by the internal success in many storage tanks which are first water pressure. An all metal tank can yield welded together and then enameled over the locally at points of stress concentration and de- Whole interior Surface.

form to redistribute the load, but substantial But however desirable this construction may yielding of a tank lined with vitreous enamel be where it is feasible, it is not practical for is likely to damage the enamel lining. Such small tanks where the limited dimensions impose yielding and consequent deformation is more obstacles on the welding of the heads to the shell. likely to occur in the heads than in the shell of or t e er tanks, a head of the form he the tank, as for manufacturing and other readescribed is preferable for manufacturing reasons it is preferred to use dished heads flatter sons. It is, however, inherently less resistant than a hemisphere. One of the important 0bto deformation than the form shown diagramjects of this invention is to provide a head rematically in Fig. 4.

sistant to deformation and particularly well As shown diagrammatically in Fig. 5, in which adapted for use in vitreous enameled tanks; a p n or uncorrugated head i portrayed, the

Referring to the drawing, the head I is of tendency of water pressure acting in the direcdished or crowned shape with a reverse flange 2 tion of the arrows is to bow the flanged head H for attachment to the shell 3 of the tank by outwardly and cause it to assume a form indimeans of a weld 4. A plurality of radial corrucated at l2. It has been found by experiment gations 5 are formed in the head, narrow at the that provided the shell l3 and weld l4 uniting center and widening towards the circumference. the head H to the shell are of sufficient strength, Four legs 6 are shown formed integrally with the head can actually be bowed outwardly. Any

the head and adapted to support the tank, or a such movement causes severe deformation in casing around it, but the legs form no part of parts of the head, particularly those parts where this invention and may be omitted if so desired. the section l5 of relatively large curvature joins No opening for the attachment of water pipes is the head and the reverse flange. While in actual shown in the head illustrated in the drawing but use, the pressure is below that needed to blow one can be provided if desired, preferably in the out the head, it can be readily appreciated that center of the head. even the normal water pressure has a tendency The head is formed by pressing and given an to cause severe deformation of the head near its enamel coating 1 on the surface that is to be circumference. This is, of course, highly undesirable since the effect is injurious to the enamel.

The effect of the corrugations in the head or this invention is to stiflen it against the action 01' the water pressure and to reduce the deformation which would otherwise occur. As a consequence the head can be made of thinner and lighter metal than would otherwise be the case. The shape of the corrugations, themselves, is such as to eliminate stress concentrations and to provide a fairly large curvature of surface for receiving the enamel.

I claim:

In a tank having a vitreous enamel lining fused to the steel wall thereof, an outwardly dished head disposed in and closing the end of said tank, said head having its peripheral portion reversely curved into a peripheral flange with the outer edge of the flange secured to the body of the tank and having radial flutes in the dished portion of the head extending into the reverse curvature between said dished portion and the flange to reenforce the same and prevent stress concentrations tending to crack the enamel.

JOHN M. FLOYD. 

